9 15 *The denominator must be the same. 9 4 36
--- + ---- = --- × --- = ----
10 40 10 4 40
36 15 51 *Then simplify.
--- + --- = ----
40 40 40
51 11 * This the answer
--- = 1 ---
40 40
Answer:
<u>The equations system is:</u>
<u>x + y = 10</u>
<u>0.5x + 0.9y = 6</u>
Step-by-step explanation:
1. Let's review the information given to us to answer the question correctly:
Liters of 60% acid solution needed = 10
x = Number of liters of the 50% solution
y = Number of liters of the 90% solution
2. Which equation represents the total liters of acid that are needed?
There are two equations needed:
The first one related to the total liters needed, 10 in this case:
x + y = 10
The second one related to the acid concentration of the 10 liters:
0.5x + 0.9y = 10 * 0.6
0.5x + 0.9y = 6
<u>The equations system is:</u>
<u>x + y = 10</u>
<u>0.5x + 0.9y = 6</u>
Solving for x and y in the 2nd equation, we have:
0.5 (10 - y) + 0.9y = 6
5 - 0.5y + 0.9y = 6
0.4y = 6 - 5
0.4y = 1
y = 1/0.4 = 2.5 ⇒ x = 7.5 (10 - 2.5)
The scientist can mix 7.5 liters of the 50% acid solution and 2.5 liters of the 90% acid solution to get the 10 liters of the 60% acid solution.
7+7=14
Hope this helps!! <3
Answer:
-6
Step-by-step explanation:
-6 is the y-intercept :)
![\bf ~~~~~~~~~~~~\textit{angle between two vectors } \\\\ cos(\theta)=\cfrac{\stackrel{\textit{dot product}}{u \cdot v}}{\stackrel{\textit{magnitude product}}{||u||~||v||}} \implies \measuredangle \theta = cos^{-1}\left(\cfrac{u \cdot v}{||u||~||v||}\right) \\\\[-0.35em] \rule{34em}{0.25pt}\\\\ \begin{cases} u=i+\sqrt{7}j\implies &\\\\ v=-i+9j\implies & \end{cases} \\\\[-0.35em] ~\dotfill](https://tex.z-dn.net/?f=%5Cbf%20~~~~~~~~~~~~%5Ctextit%7Bangle%20between%20two%20vectors%20%7D%20%5C%5C%5C%5C%20cos%28%5Ctheta%29%3D%5Ccfrac%7B%5Cstackrel%7B%5Ctextit%7Bdot%20product%7D%7D%7Bu%20%5Ccdot%20v%7D%7D%7B%5Cstackrel%7B%5Ctextit%7Bmagnitude%20product%7D%7D%7B%7C%7Cu%7C%7C~%7C%7Cv%7C%7C%7D%7D%20%5Cimplies%20%5Cmeasuredangle%20%5Ctheta%20%3D%20cos%5E%7B-1%7D%5Cleft%28%5Ccfrac%7Bu%20%5Ccdot%20v%7D%7B%7C%7Cu%7C%7C~%7C%7Cv%7C%7C%7D%5Cright%29%20%5C%5C%5C%5C%5B-0.35em%5D%20%5Crule%7B34em%7D%7B0.25pt%7D%5C%5C%5C%5C%20%5Cbegin%7Bcases%7D%20u%3Di%2B%5Csqrt%7B7%7Dj%5Cimplies%20%26%3C1%2C%5Csqrt%7B7%7D%3E%5C%5C%5C%5C%20v%3D-i%2B9j%5Cimplies%20%26%3C-1%2C9%3E%20%5Cend%7Bcases%7D%20%5C%5C%5C%5C%5B-0.35em%5D%20~%5Cdotfill)
![\bf u\cdot v\implies (1)(-1)~+~(\sqrt{7})(9)\implies -1+9\sqrt{7}\implies 9\sqrt{7}-1~\hfill dot~product \\\\[-0.35em] ~\dotfill\\\\ ||u||\implies \sqrt{1^2+(\sqrt{7})^2}\implies \sqrt{1+7}\implies \sqrt{8}~\hfill magnitudes \\\\\\ ||v||\implies \sqrt{(-1)^2+9^2}\implies \sqrt{1+81}\implies \sqrt{82} \\\\[-0.35em] ~\dotfill](https://tex.z-dn.net/?f=%5Cbf%20u%5Ccdot%20v%5Cimplies%20%281%29%28-1%29~%2B~%28%5Csqrt%7B7%7D%29%289%29%5Cimplies%20-1%2B9%5Csqrt%7B7%7D%5Cimplies%209%5Csqrt%7B7%7D-1~%5Chfill%20dot~product%20%5C%5C%5C%5C%5B-0.35em%5D%20~%5Cdotfill%5C%5C%5C%5C%20%7C%7Cu%7C%7C%5Cimplies%20%5Csqrt%7B1%5E2%2B%28%5Csqrt%7B7%7D%29%5E2%7D%5Cimplies%20%5Csqrt%7B1%2B7%7D%5Cimplies%20%5Csqrt%7B8%7D~%5Chfill%20magnitudes%20%5C%5C%5C%5C%5C%5C%20%7C%7Cv%7C%7C%5Cimplies%20%5Csqrt%7B%28-1%29%5E2%2B9%5E2%7D%5Cimplies%20%5Csqrt%7B1%2B81%7D%5Cimplies%20%5Csqrt%7B82%7D%20%5C%5C%5C%5C%5B-0.35em%5D%20~%5Cdotfill)
make sure your calculator is in Degree mode.
